This invention relates to industrial screening equipment and more particularly to novel non-clogging screen cloth assemblies.
A very pressing problem exists in the screening art, particularly when screening finely divided material, due to the tendency of the material being screened to clog the openings in the screen cloth. This condition is sometimes referred to in the art as "blinding" of the screen surface. This blinding of the screen cloth greatly impairs the effectiveness of the screening capacity of the apparatus and may even reduce such capacity substantially to zero. Various methods have been employed to remove particles which have become wedged in the openings of the screen cloth as by shaking or the like, but none of these expedients has proved effective with particles of certain shapes.
It is conventional in the art to provide a backing or supporting screen beneath the primary screen cloth but such backing screens have openings a number of times greater than the openings in the screen cloth and are provided for structural support of the screen cloth and do not of themselves perform any screening function.